<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<style type="text/css">
h1{
  background-color: green;
}
</style>
<link rel="stylesheet" href="first.css">
</head>
<body>
<h1 style="color: red;">今天贼冷</h1>
<h2 style="color: green;">今天星期一</h2>
<p>又该吃饭了</p>
<p>吃点啥呢</p>
</body>
</html>